The city management: methodological considerations on multriple criteria techniques for the selection and aggregation of criteria

The scientific community recognizes that factors such as “social cohesion”, “social quality”, “social capital” and other have a strategic role in the evaluation of the en-richment or the impoverishment of society which occurs in urban environment. These factors are used to evaluate the quality of a social system and to discriminate between different policy alternatives in the management of the city. Social cohesion, quality, equity, progress, etc. are aggregate indicators of urban quality, as they incorporate various components related to multiple points of view. The scientific community and some national and international institutions have proposed different sets of indicators for the estimation of the said global indices of the condition of the social environment. Typically, these sets contain a very large number of indicators. However, the multicriteria analysis of city policies may require smaller systems, more manageable and easily detectable with a lower burden of resources, or even a single index. This raises the need to identify suitable tools for the aggregation of criteria and/or the reduction of the number of the original indicators, in order to obtain a new set containing only the most significant factors. The calculation of aggregate variables of social or other nature may be directed to the evaluation of actual conditions existing in the socio-spatial context in consideration, or to the selection, sorting or classification of a number of possible alternatives for devel-opment. The knowledge of the conditions implied by the different models of aggregation is essential for choosing the most consistent approach with the preferences of the decision maker and for a better understanding of the assumptions, limitations or advantages de-riving from the techniques used in decision-making. This paper, after identifying the main peculiarities of the sets of social indicators, provides some methodological considerations on the most suitable methods for the synthesis of the indices, the choice of indicators and the multicriteria decision making in the evaluations for the planning, design and control policies for the management of the city